Safely transporting sports equipment is a concern for many sports enthusiasts. For example, transporting a bicycle by automobile has many safety concerns. If a bicycle rack were to become disconnected from a vehicle while driving it could damage the rack and a bicycle being transported and affect the safety of other motorists. One way to secure a rack to a vehicle is to insert an insert bar into a hitch on the vehicle and insert a pin through corresponding holes in the insert bar and the hitch. However, sometimes the receiver tube of the hitch is larger than the insert portion of a carrier rack. For example, a hitch-rack load carrier may be 1.25 square inches at its lead-in end, while the corresponding aperture on the hitch might be 2 square inches. Various embodiments of the technology pertain to a hitch assembly with an expander to enable a suitable connection between a hitch and a carrier. Various embodiments of the technology pertain to an adapter assembly which can enable a suitable connection between a hitch and a carrier.